[Coco] Multi-Pak card edge connectors.

[jdaggett at gate.net]

On 14 Jan 2010 at 21:16, Gene Heskett wrote:

> Also, using the S family of chips makes it very power hungry, and I don't 
> believe there is anything in this whole thing that cannot also be done with 
> the HCT chip family (<1% the power needed compared to S) unless that 
> particular function is not available in HCT, in which case I'd use the next 
> lowest power, probably the LS stuff.



Gene

I agree that there is no need for standard Schotky devices. Darn things are power hungry. 
HCT is the a better route. The Coco does not run that fast to require such devices. Also you 
can run into issues where an LS device driving one or more Schotky gates can run into fan 
out issues. Great care should be taken when mixing Schotky and LS devices so that you do 
not exceed the fan out of the LS devices. 

The input impedance for LS devices is in the order of 20K. Schotky devices are around 3K 
impedance. Also Schotky devices has a lower short circuit resister. Standard Schotky can 
source twice the current of an LS device. 

james